Do you have the latest BIOS? Are all your drivers up to date? You said you reinstalled about 2 months ago, and did basic, did you use the generic windows drivers or install all the latest drivers? Here is the link to your USB 3.0 Driver
, just select your operating system and it will be at the very bottom of the page.
I also tend to agree with PCstudent, as you stated you had issues ever since a RAM upgrade, could be a bad stick, or it could be a BIOS issue (I would make sure that you have the latest bios), if that doesn't take care of the issue, then run Memtest86+
, you can run it from CD or USB thumb drive.